End of Light is the debut EP by Opsis, a band whose name is taken from one of the categories of Aristotle's poetics. The EP consists of three tracks and is inspired by Isaac Asimov's 1941 short story "Nightfall", which tells of a world that has never known night and prepares for the first solar eclipse in its recorded history. The band offers its own interpretation of the story, centred on a desire for revolution and emancipation from fear. The opening track, at 13 minutes, accounts for roughly half of the EP's running time. It begins with a long semi-spoken introduction that presents the world of Lagash, then develops into heavy rock with psychedelic and jazz influences, including angular arpeggios, mild dissonances and saxophone interludes.